ORP sensors and transmitters

Products for effective ORP measurement in all industries

Reliable ORP sensors and transmitters provide trend information on the disinfection ability in drinking water or swimming pools, aeration control in wastewater treatment plants and the detoxification of electroplating baths or flue gas scrubbing. We offer an extensive portfolio for standard or hygienic applications and hazardous areas. Learn more about our ORP sensors, transmitters, assemblies and calibration solutions by clicking on the button below.

How to select ORP electrodes

Our ORP sensors and transmitters are used in many industries. Such as: chemical, water & wastewater, power, pharmaceuticals and pulp & paper. The selection of the sensor depends on the application. ORP probes with gold electrodes are suitable for oxidation processes, e.g. cyanide oxidation or ozone measurement. Platinum electrodes are used in reducing processes such as chromate reduction or chlorine dosing. Select the ORP electrode's diaphragm and reference system according to your needs.

ORP measurement

The redox potential is a unit of measurement for the activity of electrons in aqueous media. A precious metal electrode (silver, gold or platinum) acts as the measuring element where the active electrons attach. The potential measured at this electrode depends on the number of active electrons in the medium. ORP probes contain an integrated silver/silver chloride (Ag/AgCl) reference system that serves as the required reference electrode with a constant potential.

The ORP value is calculated from the potential difference between the reference and the measuring system using the Nernst equation. It is indicated in mV.

Since all ORP pairs in a process make up the oxidation reduction potential, the ORP value is a sum parameter that cannot provide information on the individual substances in a medium or their concentration. The redox value depends on the temperature and it always needs to be indicated to compare measurements.